On the Relationship between Robustness to Incomplete Information and
Noise-Independent Selection in Global Games

This note demonstrates that
a symmetric 3 × 3 supermodular game may fail to have any equilibrium robust to incomplete information.
Since the global game solution in symmetric 3 × 3 supermodular games is known to be independent of the noise structure,
this result implies that a noise-independent selection in global games may not be a robust equilibrium.
Our proof reveals that the assumption in global games
that the noise errors are independent of the state imposes a non-trivial restriction on incomplete information perturbations.
Journal of Economic Literature Classification Numbers: C72, D82.